Induction furnace for horizontal, continuous metal casting



Jam 33, 26? A. J. WERTLI 3,324,935

INDUCTION FURNACE FOR HORIZONTAL, CON'IINUOUSMETAL CASTING Filed May 22,1964 United States Patent 3,324,935 INDUCTION FURNACE FOR HORIZONTAL,CONTINUOUS METAL CASTING Alfred J. Wertli, 15 Poststrasse, Winterthur,Switzerland Filed May 22, 1964, Ser. No. 369,563 Claims priority,application Switzerland, May 25, 1963, 6,476/ 63 6 Claims. (Cl. 164-281)The invention relates to an induction furnace for horizontal, continuousmetal casting, having an outlet in the lower portion of the furnace forreleasing the melt.

In conventional induction furnaces of the aforesaid type the current inthe melt produced by the electric field causes difficulties when castingbecause this current disturbs flow of the melt into the mold whereby thequality of the cast metal is impaired.

It is the object of the invention to provide an induction furnace forhorizontal, continuous metal casting which avoids the difficultiesexperienced with conventional induction furnaces, by providing a hollowbody at the outlet of the furnace which body extends into andcommunicates the interior of the furnace to the mold. The hollow bodyextending into the furnace intercepts the current in the melt caused bythe electric field and effects calming of the metal flowing through thehollow body before the metal reaches the mold. There are therefore noeddy currents in the melt before entering the mold which facilitatescasting and improves the product.

The novel features which are considered characteristic of the inventionare set forth with particularity in the appended claims. The inventionitself, however, and additional objects and advantages thereof will bestbe understood from the following description of embodiments thereof whenread in connection with the accompanying drawing, the one figure ofwhich shows a longitudinal section through the lower part of a furnaceaccording to the invention.

Referring more particularly to the drawing, numeral 1 designates aninduction furnace having an outlet opening 4 in the outer wall 2 closeto the bottom 3 of the furnace for releasing the melt, a mold 5 beinginserted from the outside into the opening 4. The mold 5 is replacea-blyconnected to the wall 2 and is surrounded by a conventional cooler 6.The furnace 1 has an inner wall 7 which extends around a vertical axis 8and confines a space 9 which contains induction coils arranged in theconventional manner and not shown. An annular space 10 is formed betweenthe inner wall 7 and the outer Wall 2 of the furnace which space isentirely or only partly filled with melt during operation of thefurnace.

A hollow body 11 is connected to the furnace wall 2 at the outletopening 4 and extends into the space 10 containing melt, for conductingmelt to the mold 5 connected to the outlet opening 4. The hollow body 11is made of refractory material and has a configuration similar to thatof a quarter bend. The body 11 has an inlet opening 12 placed in ahorizontal plane at an elevation somewhat higher than the upper part ofthe outlet opening 4. The area of the inlet opening 12, which may beround or oval, is smaller than that of the outlet opening of the hollowbody and the flow area of the conduit formed by the hollow bodyincreases gradually from the inlet opening to the outlet opening of thehollow body 11.

Before casting, the space 10 in the furnace 1 is filled with liquidmetal to above the inlet opening 12 wherefrom the metal flows throughthe hollow body 11 into the mold 5 where the metal solidifies with theaid of the cooler 6. The solid metal is gradually pulled out of the moldby conventional means, not shown. The hollow body Patented June 13, 196711 intercepts in the neighborhood of the outlet opening 4 the current ofthe melt produced by the electric field of the induction coils so thatthis current cannot adversely affect the metal flowing into the mold 5.The metal flowing into the mold has been calmed in the hollow body 11 sothat the horizontal casting process can be operated without disturbanceand a homogenous product can be obtained.

The hollow body 11 assures efficient warming up and keeping warm of themold prior to casting and during casting intermissions because thehollow body 11 is always surrounded during these times by liquid metalremaining in the lower portion of the furnace.

Without departing from the scope of the present invention the outletopening 4 may be so designed that a plurality of molds can be connectedand a plurality of metal bars can be cast simultaneously.

I claim:

1. An induction furnace for horizontal, continuous casting of metal,comprising:

a lower furnace portion,

an outlet opening for the molten metal in said lower furnace portion,

a mold connected to said lower furnace portion within said outletopening and extending therefrom, and

a hollow body connected to said lower furnace portion at said outletopening and extending into the furnace for conducting liquid metal fromthe furnace into said mold, said hollow body having an inlet openingplaced inside said lower portion at an elevation above said outletopening whereby said hollow body interrupts the current within themolten metal to calm the metal flowing through said hollow body.

2. An induction furnace as defined in claim 1 wherein said lower furnaceportion has a side wall and a bottom, said outlet opening being in saidside wall adjacent said bottom.

3. An induction furnace as defined in claim 1 wherein said hollow bodyhas substantially the configuration of a quarter bend.

4. An induction furnace as defined in claim 1 wherein said hollow bodyhas an inlet opening placed in a horizontal plane.

5. An induction furnace for horizontal continuous castin g of metalcomprising a lower furnace portion including a vertical side wall havingan outlet opening therein for passage of molten metal through saidvertical wall,

a mold connected to said vertical wall within said outlet opening andextending therefrom, and

a. hollow body connected to said vertical Wall at said outlet openingand extending into said lower surface portion, said hollow body havingan let opening inside said lower furnace portion above said outletopening in said vertical wall.

6. An induction furnace as defined in claim 1 wherein said hollow bodyhas an outlet for releasing liquid metal into said mold, the flow areaof said hollow body increasing gradually from said inlet opening to saidoutlet.

References Cited UNITED STATES PATENTS 2,530,854 11/1950 Brennan 2257.23,022,552 2/1962 Tessmann 22-57.2 3,076,241 2/1963 Simonson et al.2257.2 X 3,125,440 3/1964 Hornak et al 22200.1 X 3,210,812 10/1965Berwick 2257.2

I. SPENCER OVERHOLSER, Primary Examiner.

R. S. ANNEAR, Assistant Examiner.

1. AN INDUCTION FURNACE FOR HORIZONTAL, CONTINUOUS CASTING OF METAL,COMPRISING: A LOWER FURNACE PORTION, AN OUTLET OPENING FOR THE MOLTENMETAL IN SAID LOWER FURNACE PORTION, A MOLD CONNECTED TO SAID LOWERFURNACE PORTION WITHIN SAID OUTLET OPENING AND EXTENDING THEREFROM, ANDA HOLLOW BODY CONNECTED TO SAID LOWER FURNACE PORTION AT SAID OUTLETOPENING AND EXTENDING INTO THE FURNACE